SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7ccf1c331dd52b34cf79cb7c21fbeeb33a8b84a57288c7a74c9169f154533414' 
  AND token = 'zMUF2Fr+Rf4ZYjv7cgFmeTwXSgQJ514QRwgVZX9xPp4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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