SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f98348401855e95e11b8f1cac2c3d4d7352047b1f19558179436dfcbdbf683d9' 
  AND token = 'CB+nMIWxSAg9wpVvcurMSI9QuZGSOidWw8fOu/VGJkg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}