SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dd91751c252b735bc3c5140e00184dc102f604e9833b740d99f3c03f9586b8e6' 
  AND token = 'FNKKshsDeR3AmDJ/9WiBuIVvZ7w14uwqN7rkLIYCHQA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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