SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '36e8dbd543a5a85faae604b8edf7ee7613650c53e50890d274fd6af0f2ed82e9' 
  AND token = 'syqmadyJa8MD71XRyoJaaI6fniKA6Ggh4uYCriwC6iU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}