SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '854d9f1a3eabc8b4e883fbae599dd0a500b3b1bdf6cc47ceafa491424a06c617' 
  AND token = 'oLWi+JNPra8cacDbd/N7ytzdU/GKlwNakvz7KbIm4v8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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