SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2afa38071510b54827287a31f11574c29ed5c4b8cfe59bcd8e45ba6590782939' 
  AND token = 'UuO4roSILHjL0AGhs6K4VYIhjrrvcfBi7BFCYcz1YN4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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