SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a0733ef11a5a62302a0671e8537bb737d13c1e35a9bbd93d335ab89d029da4e5' 
  AND token = 'Bq0x7IqmHS0AKnQISa6EMLDzsoI1yo3yOpNqOQN2bGk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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