SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '821c3567d845f244adc3e35b14ca7898b69f3a50e11c0dd55c20764d35cc4b54' 
  AND token = '8dmt7Zr5abc+vtNPiUmxbJls73UKKG5gNdeiQJw86cY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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