SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'afaf576233eec699521ba04a3189e490dd918a5a0efb66cb437c10d8e87e9640' 
  AND token = 'k/3GYrbRIGyKjDdVawhZBGcZ1cNQIIAbfNyIdwOLcbg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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