SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4c9f1502864c69d5b45d26bf982dd4167de36baab55bf4014e6a1bc1c9ea83ec' 
  AND token = 'YHAG7oGx7H0LqpsrjshjgZWqpXuqbxJMWm0NCHb8zGA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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