SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '87da703764604acfcd198afa6f88b683333e6cc345b9ff3d20a3f9bfc55baceb' 
  AND token = '5caKy2YcXzh66p2HyA0KuAwkoFw8y9T5svCIjCrSoOw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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