SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'ff122295950397c7aa6407a4e8e132116c5281d7c919642872d04cfcf7c0c4a6' 
  AND token = 'vexqskW5QUdzFPFJQmZLFOy8cgYtxiq96E0wZLp/ItE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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