SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9b37bd26cb160464457f414a36a80fcfc6931ee2c538d4541b8b35cda4ffadad' 
  AND token = 'pGft38/agNQUUrpgPInmYoQue+G6RWN3lZR7EDdgPjU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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