SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '255b511add3c45d4b98899f471f872de6bdada9eb2cd8cb0de2f34991228b66e' 
  AND token = 'IBe7Zv9kwJCR8DqjTtiFQrv85l/2YKg6sg+jjKgWr+Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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