SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1e46abc100102fb216276bd94f89bcee0847cba77b5eb400f48b807752cdb642' 
  AND token = 'SVEmBwRpDnnTUXgH0x2bjPdGhBRw4Xe3fn0TmeU0/ew=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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