SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6bbbc5ff2a3a15a05f278f1e0831904f40d19f347176c22ab2cdba38691fbb13' 
  AND token = 'ar4s/aI2AHMZS7BxYUFocFRm9ZS0gD3VwDUWur2lCJw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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