SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '09647c742ba162cb255ed7fbd1b810a09d6458b40fc3269f142fa2a338fb3fe8' 
  AND token = 'aYdfWlnByVbbWElgcOHKyG4m0P6wiHhwxqhJP+v29Zc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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