SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '04b9b964557223e6687cb2259d4b367d9b9bdc145a494f622381cc6b04cb1990' 
  AND token = '87dvRFoQh7uE/yoUPAtdB0B1/vywKlShZdMzdG2PXeo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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