SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cffe55a639fecff367c84faf5111799f50cb02d3b5b196159a4439178d1e971e' 
  AND token = 'ojZviOYyNqdtbHIlgjHS9I9al7MEmPISQ9TXkI2+Ml8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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