SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '757f3c6fb8cb14b946ff16ec444a6be98f917ed27bc8ab33c0211189bf992790' 
  AND token = 'ZJ9TArGKO20Eq7GJBd1XePCNtYYYfG/dIJ77shMVzK8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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