SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'dcfeaebe617b66af30793eb750242917824f616084c9a16c0c1fc7f4e8fa8be6' 
  AND token = '2IQ69dND5TqpTyoogNmn7ObAAZmvnrDmsfKHBpn+iiI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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