SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '71d26091606944e06c8cbd5d2528b77ed5a19b5d8088a2dad7b23f29bb1538f0' 
  AND token = 'vRY8/NfErLJpGyE6iYKecHvkXwR/hcIq0F+bBn6ADDU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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