SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2fb46a6febdd4fbb234d5a91f6c6903de4dcc0259cc75c209775a1cd6ffd89eb' 
  AND token = 'lgVuaCcR+Iq5SWiMinF1ubQWbATEcJeSgjQ7QW1q+3w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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