SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0175e8fee0936f48be2f6867940c4c9500a3f9f08ba358c1803c7fbeebc20336' 
  AND token = 'Muv/jo73E+pQSalwNh9xQsBo0w5LULifjt2HWAsF1hQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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