SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7eae67dd1f5f257c011da3b1fe2bd188281db53898f609bad1d6e4d37cc2c768' 
  AND token = 'tdcqlIzY+aP4CqR414eTfuNBmzw0vHyLfckQgUTA+ok=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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