SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '9fc51a55d29f3ee81376f684cbd4118f5520633dd82b939438101fef32a364a9' 
  AND token = 'f4D6WfHxhlY0BmyGKrOS2dd4iRCRQDtouJwVxXDFGpo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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