SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b20c267f365396b7d4dad930af32a5a58d93c780622653dde943937bfcf271da' 
  AND token = 'wvlneZMMqCqltKA8qLZr4ZSe2bRPdGDsfgBLoBDyXLk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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