SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2f4476b7ce4d5e4b3ca190fe83a1429a6ae056d31451968d162740a638f0030b' 
  AND token = 'iqnGR8BwIcQ6VAaZInhpDUL9e1c3GheRBiRVoUopEBQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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