SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '211593f4c4a702729eedc3826b06684755ff54456bcf2748fda7e4e081d4414c' 
  AND token = '3upwI9CRPy137/3CMoQnPUY4idJjQ0fKwq1hHxWdsqI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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