SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '41bdaf6d5f56948a2839b9f78457f0d5a2b30181be293bbbfb9520a5e428cb56' 
  AND token = 'MVqs6uYn/nDE6fCvkT1hdMtBPMoWlQ+Dz4zwexeS6nM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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