SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6624fb5ea663ca0ae674beaea68b13fabd29b93893c71be8ad73504b8f1858b9' 
  AND token = 'wXyrJK7eBEF1JfmIoYsn65gqrmYZRePekkwxgow5MhE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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