SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '58afb01fd76e7f26b34cc36e8284d8a07faddcfa50ba08756e5818825ad03941' 
  AND token = 'CeItg3AlR9XPDhZqfK4haqBcsPDpxKOAZLVd404evyU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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