SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8ed94511698bc50a9db85b2ad229aa4c9218b1b6621755afb5d23033f6867957' 
  AND token = 'Ot3E/Ib5MTTiNaWMLva6djQdcncv5iqjCo4CkhRvcek=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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