SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2b5aacde073400fc03f7ac0127ca167804146ebb1ffbcca8fcfc0f4fd047d849' 
  AND token = 'qq/kdMF1OvxJhX0WJxm+xosz1VuQxZKqfnJnHq5KdYk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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