SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0a8b575a158deba0b4147687dd15cf35c709f6f10b8a051c8bec3156444b6f28' 
  AND token = 'nwgHduEMbKC0tn9bGRdMuPzo/kT3o8EC9UTR1d2nFWg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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