SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '76bd3c1412662ece51593677f93b55fb341564875da62af99e24bbcb7f2e19ff' 
  AND token = 'sJstAhBmN6ONa0DwKiz5VFKIHhUlltFMA8iVvKdnXFA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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