SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b6ce23a7fc1fcd673c4246d9bf443955c7dfb8eff7c8ed3c7d0335086da5d9a9' 
  AND token = 'vYjkcpRDLR+ZeuhK4fqpJSIdo8Z8zIRgJ2F/P7NUxQU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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