SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '193604903c7de4d90605448c9b6b982805d80f6b5ffc42e5d6fd37d185e79e4b' 
  AND token = 'zItUkycB22S7Z1ndh8QGGoDQjm/plrRmLNV5HzbU1Zw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00055

JSON explain

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