SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7162748be958225548fb8ec7fafbf7a8deedbad56923a118cd4d7a36af1b19a1' 
  AND token = 'u05vYwjlU0qiYd0KQJZt0q+AIWbE9Sw2dsurZWlBJ8A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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