SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8d6352e3110bbe93be5e14aa79352069170ace114ebdf4b58564e600a3b6a04d' 
  AND token = 'xvcflLgT0ubS3jLX833igdnWE9AMkOdtzmjOP2YVNpQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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