SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3efe72b91f62ba3f73148cc928d2dcc6395d34f5c4e24ef039854b2c5b099a09' 
  AND token = 'RplRf09JdSYmHDaA8LQw8UYWWU9c/VN523t+Xl1VcJE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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