SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bad1aa9e71db2567468e0c2c987a5250122c874667a4c1cbe195951d9fe39a90' 
  AND token = '4tUZCXsFEI20v0Npiajf9H0HYBVYlMRVqmq3kYJENhI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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