SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c662b6103cc39bf15f3de69b7447c6e9a2074369f868f65d4e13a0378cb7d56d' 
  AND token = 'm5suOybwekfBW20Sz7BNT03Ux8M9M3wGyv3+g3jLc/E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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