SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '709fdc0a56c74a0a422f1496ca2a9ffcb2852e3ac66a0a452719bbabe8900af1' 
  AND token = '044BNOTiBjKdMVbb3DIp54XRYo5dv+tMD1wb1z+wxOc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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