SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '09c38057404ce5063923d7323f45d37025525a6c597ce14ec1748276f785db59' 
  AND token = 'G/YMPAdN8oA+7zgFXYrXVhG4uJDyuEZjdLM+GcgdRVw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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