SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dd0ae62c2d480325b21af6eaebebe7515cf6c0a4485c01c05afd4e03fecb97cc' 
  AND token = '2kMGooicl2ewMEWKhMCZ+aPUXepHi2U4cUtLNlZ1bP4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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