SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8cd953a4672528f3fe0473e0150c6843351ba643357c984a7905c237823ea156' 
  AND token = 'VBhHSH9OsUbngkiv3v7UHdqhPhaJTDY0jjPsnizUw80=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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