SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f297381b719c88844188b5b164c14b567b112da66a1346fd742101a71cf6e737' 
  AND token = 'ac0HnqxWFmvYyRO6r1sq9sPQfYGc7UMO4vLi+86vcVI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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