SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3c6e6d5ddcba0608dc235b6cb017e20f3122d33303ae6687a852d9dacc64ed0b' 
  AND token = 'ckzjL54tU3q9VLAO/mR5OMDmyM30wp26i69BIzIV0qs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}