SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '594fc381126fee0d7786eadb431f84b7fb83db9207e01a1286055381d9ff448f' 
  AND token = 'RAkB9B4wzf/z0nn0PjJfsqL2XFxh1O+QzuV/EKUMLm4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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