SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4872bbca2e9a437adf6cdbdcf711dd441657cd8d536350c00e2769214d4d83ac' 
  AND token = 'Y1KrjFBPTT2SGDGqgpP88EhGWzzliKAZTrVZ1uoUUhk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00058

JSON explain

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