SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'fdcfb55d8c54ff69317b8bb37b9035dc3cb0ed8b5e2927c85dea4da0353d78b4' 
  AND token = 'JID1AvuI+oWk2gxoxMCX9HSANNVivArD994No8MP8hw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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