SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'ab4c194e83757daa59cca0435652f77f034436f0916ff983e35752a305216bee' 
  AND token = 'QWMPPQ8monk3W3ouT66t4hzmIEKu3kxFXZX4nbHheOY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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