SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0474ec92ca373dc28a9f4c349d557c8e0425adaf329711a447897acc980577be' 
  AND token = '7es5N5xQccrQKNzRrsKSswSjWa67siHNMI9spZ3qoYI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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