SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '44a85ebcde52331f2674b229cfb5aaff9666710401ca9250fb473def1e5fc294' 
  AND token = '8CQKUocbpCU8e0FYPX+KxRq5WLjng+L1brFCGHoplD4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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