SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dce09fbfe0cdcd67f5c9abdbd4fee2e3b67bd2a7082d1e56bca599e89968e9e6' 
  AND token = 'I70u0JYErc/ie3y9+y0wC2o6cIEaZb7vGFPAG47xZxA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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