SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '03fffe510808766c4ba3bc3139e969b1d8428d6f5c3aeb536ec1bc12198d4b51' 
  AND token = 'TZuIw7TJe0UGzZKsOTgRQBj2hsnRNcoAnX6J7a4t6sA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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