SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '47b6da850b54274aebeaa0634413fcffd627cb1f9fd6b1218f12f31cc6c1342c' 
  AND token = 'Vce/lzuEbdTcyrYoIDMDhLUqcPqvllOFlj3VIYlqx3Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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