SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2c255e48769bb05b9c3c549de8e61be695ffac3c71eed8d2aef28288a3c3b9b6' 
  AND token = 'amL1HyzSARE4MmzK5CI6qe3jQb0djKTrIejoMCnRAH8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}