SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '370afadae5eceeec67b05b3ad399951a2ceaaa6f65f961a80663aad46ed52bee' 
  AND token = 'a1jN1jzfqicjwny4uGcoGcUsk1hvsq5NTfE+kXGnMu8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00053

JSON explain

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