SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a09473b90397ecdd6c36b8f6b78b841a95601e60fc8de8a2703f134aaa7360a4' 
  AND token = 'XCcx4+6/uXvSboYDnUChYBdIJ0VlqMJjeQjlyFz3tRc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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