SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2ae7741a6e1e035373346848a929e122573da448c07067d491e4bdc5530ace51' 
  AND token = 'OALkedd4UWetd1qe6FpRGZM8PnyS0bg+c9AYrGLRY0o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00063

JSON explain

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