SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '423144427740620b37aa6a3fc3fee3ffa5955ecf2f517b7b4c07865ec65fece9' 
  AND token = 'YtZ2LC7daytJhMBjvnSpFC3mA1F0E/h4718FWE/uDxY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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