SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '18e90800f17304e337cf96c994f3a6734a4c483172f3038d882ee91eb394318f' 
  AND token = 'sirmo98/KBuGFkvjKO33bzaLhZWw3hfoUUZbA//o/oY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}