SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '38bbbab31deadd35c794f5e882437765f64963e8ff90c0f2dd0488972e7224f4' 
  AND token = 'qynC9b7GVACR9QW7TFaqp1pGh7UVlqdPJcljrVntFNw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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