SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '1be2f13d2a3d2e4d29818b0692f17024d5957a0d91bc5704af5fe82215ff12c9' 
  AND token = 'sYxTjb1Dajeqi88zCQGP11X9aG+2OamRYlo47bZBkG8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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