SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4188f114c2284125b2348def06184441f437daa220904f0ca34825ee54fd2473' 
  AND token = 'iIyOVyMI5Z9LFWTof1w4FiePewSNxb5vwz32F7tcPHs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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