SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '5b52ec905af748871de3bdcc58080f57e6dde4a46b9e41dad57a39ad88723898' 
  AND token = 'NfK0Z/c33PA/tuehApidcaGMldauO2ZvqrKkzH4PlDA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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