SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '673c3c1f402c1883dcc2e94090588be32ee35bd6151409edfcfd80f5ec78df17' 
  AND token = 'GE4vynvcZBPX3tU+28XUmT9KcibCxc0Usscl6fSn4us=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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