SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c7cdf5cad9ece776938f8d2606cc091dcf3fb6fffafc9eb8fab4ca672fb6d201' 
  AND token = 'QHq9DFORijM8FpkgfYs2045BZEQ6TVGjFRBglk5s8Mo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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