SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '48ff00ba886f8bdbdf215e303b87c1ef5564ad4f55408c5333f707892be8e477' 
  AND token = 'b/CGg6lDS1TyxjuvNeKeUX/YxD2Hk9BIZIm2Fhe7LRM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}