SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd2c9d0f86a9cec0d212191ea45f693c2aa4ac63bedd3f099a60f484a2feac0c5' 
  AND token = 'oD9MZ0kqTxJmnFSNCCOuJQJZMFA2yyDndGPaZkouFzY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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