SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '98d792ca1756e631834c05f90db152d4360fa8c57e73e2ec6a82f072d18d9945' 
  AND token = 'pTllyo7GsFGsTn3fW8H+FoWybBIfiSdhjmHStdcclrM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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